1. Field of the Invention
The present invention relates to an electrically operated camera having a means for detecting the film feed condition that is capable of determining whether a film is loaded or not on the basis of the output of the detection means.
2. Related Background Art
Among conventional electrically operated cameras, cameras of a certain type are known, which have a film detection switch (hereinafter abbreviated as "film detection SW") for determining the presence or absence of film, as well as a feed detection switch (hereinafter abbreviated as "free sprocket-hole SW") for determining the film feed condition, and which are thus adapted to determine the presence or absence of film and the film feed condition separately.
Such a conventional camera, however, entails high production cost because it is provided with both a film detection SW and a free sprocket-hole SW. In order to lower production cost, cameras of a different type are known, in which the film detection SW is omitted, and the presence or absence of a film is determined on the basis of the presence or absence of a free sprocket-hole signal (hereinafter abbreviated as "FSS"), a single signal thus being used for both functions.
In a conventional camera of this type, after the completion of one photography operation by the user, a film rewind action is automatically effected. Also, release lock is effected so that no shutter release can take place even when the user inadvertently actuates the shutter release button, thereby preventing the exposed frame of the film from being subjected to any further photography exposures.
The conventional camera, however, entails the following problem because the presence or absence of film is determined on the basis of the presence or absence of the FSS in the free sprocket-hole SW. When the release button is actuated when no film is loaded in the camera, since no FSS is detected during the film winding action, it is erroneously determined that the terminal end of the film has been reached, and the film rewind action automatically takes place. After the completion of the film rewind action, the camera is brought to its release lock state, as it is when a film is loaded and release lock is effected after the completion of the film rewind action.
In brief, the conventional camera is such that it is brought to its release lock state after a film rewind action, whether it is loaded with a film or not. This is disadvantageous in that, when it is necessary to check various actions of the camera while no film is loaded therein, the checking can be hindered by the release-lock state of the camera, in which it provides substantially no action.